Trench bucket



R. B. MURDOCK TRENCH BUCKET June 1, 1937.

Filed Nov. 7, 1935 III! 16 25 2O lNI E NT0 ROBE/P7 B.

MURDOCK Patented June 1, 1937 UNITED STATES PATENT OFFIEI 5 Claims.

This invention relates to improvements in excavating buckets and more particularly to buckets of the type having bottom dump mechanism.

One of the objects of my invention is to provide 5 an improved bottom dump excavating bucket which will be of rugged construction, easy to handle and requiring little headroom for dumpins.

A specific object of the invention is to provide an improved bottom dump excavating bucket in which the bottom is so pivoted to the body portion of the bucket that the center of gravity of the bottom will move downward relatively little when the bottom is released and so that opening and closing of the bottom is relatively easy, the bottom normally hanging ajar when unlatched, and at such an'angle that the bucket is completely selfemptying under the influence of a load on the bottom.

Another object of my invention is to provide an improved excavating bucket of the bottom dump type in which the bottom is so hinged that it will tend to move on a constant axis, and through a long radius, relatively flat are requiring relatively 35 little clearance for complete discharging of the bucket load.

A further object of my invention is to provide an improved bottom dump excavating bucket having a sensitive, gravity actuated, latch which will cooperate automatically with a high hinge structure for the bottom and will automatically lock the bottom in a closed position when the bucket is pushed to cause a relative rotation of the bottom.

an improved excavating bucket of the bottom dump type which is especially suitable for operations in trenches, etc., having a minimum of clearance.

Further objects and advantages of my invention will appear from the followingdescription of a preferred form of embodiment thereof taken in connection with the attached drawing in which:

Figure 1.is a substantially central vertical sectionzof my improved bucket showing in dotted.

A further object of my invention is to provide.

Figure 5 is a partial front elevation of the bucket with parts of the latch mechanism in section.

The bottom dump bucket illustrated is especially adapted for excavating operations carried out under conditions of relatively low clearance as in relatively short, low or narrow trenches which are inaccessible to larger machine equipment, such operations commonly requiring hand filling with dry material such as rocks, dirt, etc. While my bucket may also be used for many other purposes such as transportation and handling of building materials generally, its relatively rigid, light weight, and completely discharging characteristics make it especially suitable for the excavation work. Furthermore, I have provided an easily closeable, minimum clearance bottom for the bucket which will completely discharge all of the contents of the bucket although it normally opens on a long radius; relatively flat arc and thus takesup a minimum of space.

In the embodiment of my invention illustrated a cylindrical shaped bucket I0 having a suitable steel sheet body portion forming side walls ll is preferred. This-body portion may conveniently be made of a single piece of metal rolled into the desired shape and. welded or otherwise made secure. The top is normally open to be filled with the excavated dirt, rocks, etc., and I prefer to reinforce the top such as with a band of metal l2 which will form a ring at the top of the walls.

The ring I2 is placed inside of the bucket to restrict the opening so that everything that will pass into the top, will also be freely dischargeable out of the bottom. Other means may be provided, however, so that the larger openinggis at the bottom to expedite discharge.

This larger bottom opening is closed by a hinged closure member generally shown at M which is hereinafter referred to as a'door. The door is carried on a rigid frame having a generally L shape, the upper part of which forms the pivoted hinge and the lower part supports and reinforces the door. As particularly; shown in Figure 2, the reinforcedfframe for the bottom of the door may consist of-a plurality of angle bars [5 and I6 which may beplaced in a Y shape, the extended portions being adjacent the pivoted edges of the bottom and the restricted portion being placed adjacentthe latohside. A transverse angle bar I! also tends .to support the bottomplate. This bottom door is'formedof a sheet steel plate which is preferably of theasame. gauge as the side walls of the bucket .andcis smooth and flush to facilitate discharge of material therefrom. A ring [4a surrounds the door and serves as an additional support for the edges.

Extending from and integrally secured to the door brace angle bars l5 and it, are L shaped bars l8 and iii which form the vertical portion of the i. shaped hinge. These hinge extension bars i8 and i9 extend upward along the side walls l I of the bucket as shown in Figures 1 and 4 to a point well above the center of the bucket, and are apertured at the top to receive the hinge pin it. Preferably, they are reinforced at the elbow by supplemental angle bars 25. The body of the bucket is cut away at Hot for free movement of the door to a flush position.

The fixed part of the hinge includes suitable .-orced angle brackets 23 and 24 which are r1 /eted or welded to the side walls H of the bucket, such brackets being provided with suitable apertures serving as journals for the pivot pin 2!. The fixed hinge brackets 23 and 24 are suitably spaced from each other and the movablehinge extensions l5 and iii are also suitably aoed from each other, such spacing being maintained by cross braces 2t and by the spacer 98 which may be a suitable length of pipe. The spacing of the hinge elements has the effect of a long hinge pin and insures the movement or" the door in a plane perpendicular to the pin. A shield 27? covers the top of the hinge and is adapted to keep out dirt, etc., and prevent wedging of rocks under the spacer.

The hinge pin is placed at a point above the horizontal center line of the bucket. As shown in Figure 1, this permits a free movement of the door it and allows it to take a partially open position when unlatched. In the specific structure shown in which the diameter and height of the bucket are approximately equal, the bottom normally opens at about a thirty degree angle and I find that a load which is carried in the bucket will completely and rapidly discharge therefrom. While a greater opening could be obtained by reducing the elevation of the hinge pin the center of gravity of the door would also drop to such an extent that it would take much greater eiiort to close the door and it would require a larger clearance for discharge.

When the bottom is hinged as shown, a very simple push on the bucket in a plane transverse to the hinge pin will cause the bottom to snap into closed position as the center of gravity drops so little that this action will take place. I therefore provide an automatic, gravity actuated, latch which will be sensitive to this slight motion of the bottom and will hold the bottom in closed position.

One specific form of latch for the door as shown in Figure 5, includes a freely pivoted dog 30 mounted on pivot 3i and so counterweighted that it would normally hang in an open position such as indicated in the dotted lines of Figure 5. It has a pin retaining hook 32a and above it, a dog closing surface 36b, and a keeper contacting portion 380 with which the keeper 32 cooperates. The keeper which is pivoted at 33 and has an operating handle 34, tends to drop by gravity so that it will normally be in position to contact with the dog as.

The operation of the latch is as follows: When the door 14 is open, the dog Sil hangs in the dotted line position of Figure 5 with the keeper in the full line position. The contact of the heel 38d of the dog with the side of the latch housing prevents the dog from falling further. As the door is closed, the latch pin 36 which is integrally secured to the door engages the dog closing surface 381), thus rotating the dog clockwise about its pivot and bringing the pin retaining hook 380. into operation. At the same time, the other end of the dog 3t forces keeper 32 into raised position after which it drops to lock the dog closed.

When it is desired to release the door l t to discharge the contents of the bucket or for other purposes, the keeper $2 is raised to disengage the latch portion 380 of the dog, whereupon the dog 38 swings by gravity, assisted by the weight cf the material resting on the door i l to the dotted line position of Figure 5 to permit the door to swing open. This construction therefore provides a latch for the door 14 which automatically catches when the door it is swung into closed position and which also automatically reieases the door it when the keeper 32 is raised.

The latch mechanism is covered with a housing to keep out foreign matter and the end 34 of the keeper 3? projects out through a slot in the housing 35 to a position where the attendant can reach the same to release the latch and discharge the bucket. By pivoting the keeper 32 so that upward movement of the end 34 is necessary to release the latch there is little danger of the door I4 being acidentally opened during the hoisting operation as any obstructions which might strike the end of the keeper as the bucket is being elevated will tend to seal the keeper more securely rather than to release it.

The construction above described possesses several advantages, which so far as I am aware, have not been present in the trench buckets known to the prior art. By virtue of the cylindrical form of the body portion of the bucket and re-enforcing ring i2 on the inside of the body portion adjacent the top opening, a construction is provided which will receive loads consisting of heavy boulders and the like, but which will not accommodate boulders of such a size that they cannot pass freely through the bottom opening of the device. An additional improved feature of the illustrated embodiment of my invention consists in the arrangement whereby the outside horizontal dimensions of the bucket adjacent the bottom thereof are greater than any corresponding dimensions in the same vertical plane above.

This feature insures that the bucket when used for trench work will not wedge between closely set bracing, but instead will either pass freely between such bracing into the trench or will abut the bracing so that it cannot pass therebetween. A common disadvantage of the buckets heretofore known is that the outside dimensions of the bottom portion thereof were smaller than the corresponding dimensions above and hence such buckets were subject to the objection of entering between closely set bracing and wedging therein.

Transportation of the bucket when filled is usually by grapple hooks and a chain and I prefer to reinforce the eyes 38 for this purpose. The hooks 39 will readily engage the eyes but, if desired, trunnions could be secured to the outside of the bucket for a similar purpose. When the bucket is raised from a position on the ground, the bottom cannot open as the latch has closed automatically and the bucket may be used with safety over the men. The normal weight of the bucket, although approximately but one-half that of equivalent capacity buckets, is sufficient to assure closing and locking of the bottom when it is set down on the ground.

While I have shown and described a preferred form of embodiment of my invention, I am aware that modifications may be made thereto and that size and shape may be varied without departing from my invention. I therefore desire a broad interpretation of my invention within the scope and spirit of the disclosure herein and of the claims appended hereinafter.

I claim:

1. An excavating bucket of the class described including a body portion having an opening in the top and an opening in the bottom and a closure member adapted to close the bottom opening, said top opening being smaller than the bottom opening whereby material filled in said bucket will completely discharge therefrom, means to hinge said closure member at a point substantially above the center line of the body portion the distance between said point and the bottom of said bucket being greater than the radius of said closure member whereby said closure memher will open by gravity on a shorter radius than the diameter of the closure member and will close automatically when subjected to relatively small forces applied transversely to the axis of said hinge means, and means responsive to closing movement of the closure member to latch the same in closed position.

2. An excavating bucket of the class described comprising a pivoted bottom, a latch bolt extending therefrom, and a latch to automatically engage said latch bolt and hold said bottom in a locked closed position, said latch including a dog having a dog closing portion and a latch bolt holding portion and a counterweighted portion, said counterweighted portion normally holding the latch holding portion in an open position,

and a keeper mounted adjacent said dog, said keeper being adapted to drop by gravity into position to lock said dog in a latch bolt holding position.

3. An excavating bucket of the class described having a body portion, the height of which is substantially equal to its diameter and having a hinged bottom, a hinge therefor including a plurality of reinforcing members extending substantially across the bottom and up the side of the body portion in L shape relation, means to space said hinge members from each other, said spacing means establishing relatively separated hinge points, said hinge being pivoted to said body portion at a point above the center line thereof whereby said bottom swings through a relatively long radius, shallow arc to require the least clearance for complete discharge, the center of gravity of said bottom being so placed that the bottom may be closed by a relatively slight movement of the bucket in a plane transverse to the hinge axis, and a latch to automatically receive and look a projection of said bottom when said bottom is swung closed, said latch including a latching element normally in open inoperative position, means responsive to contact by the projection of said bottom during a closing movement of the same to receive and hold said projection, and releasable means operative after said latching element has moved to closed position to retain the same in such position.

4. In a self-dumping excavating bucket of the type described comprising an open body member, a door closing the bottom of the body member, and means pivoting the door to one side of the body member, means for latching the door in closed position comprising a latch pin on the door opposite the side at which the door is pivoted, a pivoted latch member cooperating with said latch pin on said door, said latch member having a hook surface to retain said pin and a cam surface which is engaged by said pin to swing the latch into closed position, and releasable keeper means to engage the latch when it is swung into closed position to retain said latch and said door in closed position.

5. In an excavating bucket of the class described comprising a body portion having top and bottom openings, a door to close said bottom opening and a hinge arm extending adjacent a side of said body portion and having one end connected rigidly with said door and another end pivotally mounted on the side of said body portion at a location intermediate the top and bottom thereof, releasable latching means for holding said door in closed position comprising a member on said door and cooperating elements on said body portion adjacent the bottom thereof including a latching element normally in open inoperative position, means whereby the closing movement of said door moves said latching element to a closed position in which it receives and holds said member, and releasable means operative after said latching element has moved to closed position to retain the same in such position.

ROBERT B. MURDOCK. 

